Well pipe expander



Feb. 10, 1953 P. B. CLARK WELL PIPE EXPANDER 2 SHEETS-SHEET 1 Filed Nov. 28, 1950 foul-.81

A A i POU/ 5. C`/Gr/f i INVENTOR.

Feb. l0, 1953 P. B. CLARK 2,627,891

WELL PIPE EXPANDER Filed Nov. 2e, 195o 2 SHEETS- SHEET 2 Pou/ 5. C/Or/f INVENTOR.

A T TOR/Vf Y Patented Feb. 10, 1953 UNITED STATES PATENT OFFICE 7 Claims.

The invention relates to a pipe expander for use in a Well Where a string of pipe has become indented or collapsed, usually due to the application of an external pressure which results in a reduction in the internal surface of the pipe.

Expanders of this type are generally known and one such device is shown in the applicants prior Patent 2,499,630 for a casing expander issued March '7, 1950. The present invention is in the nature of an improvement wherein the rollers may be manipulated and moved radially outward to eiect the expansion of the pipe with a view of restoring it to its original internal contour.

It is one object of the invention to provide a pipe expander wherein a mandrel has a sleeve slidable thereon where such sleeve carries a plurality of rollers which can be moved radially outward due to a wedging action because of longitudinal sliding movement of the mandrel inside of the sleeve or housing.

Another object of the invention is to connect a mandrel to a string of pipe in the well so that lowering and locating movement may be imparted to the mandrel in order to expand the pipe surface by a rolling action.

Another object of the invention is to provide a housing which is slidable but non-rotatable with respect to an internal mandrel and wherein rollers carried by the housing are engaged by a tapered area on the mandrel to extend or expand the rollers against the pipe. L

A still further object of the invention is to provide a mandrel key for sliding movement in a housing and with a plurality of rollers keyed on the mandrel so that rotation of the mandrelefifects rotation of both the housing and the rollers.

A still further object of the invention is topro'- vide a pipe expander wherein a circulation of liquid may be had from the operating pipe around the roller to assist in the manipulation of the roller. 1-

A still further object of the invention is to provide a sliding bearing in a pipe roller sleeve for the driving mandrel.

Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawings wherein:

Figure 1 is a vertical sectional view of the casing roller being lowered into position in a pipe which has been deformed in the well so that the expander may be manipulated to restore the pipe to its original contour.

Figure 2 is an exploded view of the housing and mandrel ready for assembling.

Figure 3 is a transverse section taken on the line 3-3 of Figure 1.

Figure 4 is a vertical section somewhat simit ing been lowered to expand the rollers against the casing, and wherein the casing has been restored to its original contour.

Figures 5, 6, 7, 8, and 9 are transverse sections taken on the corresponding numbered section lines of Figure 4.

In Figure 1, a string of pipe 2 is shown as having been positionedA in a well bore but an area 3 of such pipe has become indented or collapsed, usually on account of a pressure upon the formation 4 to effect such a change in the` contour of the pipe which usually reduces the internal area or diameter.

A pipe expander, designated generally by the numeral I0, in accordance with the illustrative embodiment, comprises a mandrel, designated generally by the numeral I I, inserted within the bore of a generally tubular housing or sleeve, designated generally by the numeral 30. The upper end of mandrel Il is attachable to a string of operating pipe I3, having a iluid conducting passage I4, by means of a coupling I2 having lateral discharge ports I 5 communicating with passage Il! for discharging fluid from passage I4 to the exterior of the tool.

As best seen in Fig. 2, mandrel Il is provided about its upper portion with a plurality of radially projecting, arcuate drive lugs I6. The latter are of elongated generally rectangular shape provided with longitudinal side edges I'I, the spaces separating the lugs forming elongated spline slots for purposes to appear hereinafter.

The intermediate portion of mandrel II, beginning at a point below lugs I6, is downwardly and inwardly taperedto form a generally frustoconical expander 22, the lower end of which is extended into an elongated cylindrical portion 26 having a diameter substantially equal to that of the lower end of expander 22 and less than that of the upper portion of the mandrel. Cylindrical portion 26 is provided, immediately below the lower end of expander 22, with a second series of radially projecting drive lugs 25 generally similar in size and shape to lugs I6 and in longitudinal registration therewith. Cylindrical portion 26 below lugs 25 is provided with external threads 2l adapted to receive one or more internally threaded spacer washers 28 which are locked in position on portion 2S by means of an elongated lock nipple 29 which is screwed over the lower end of portion 2G andmay extend below the same. Washers 28 and nipple 29 are designed to serve as a bearing support for the lower end of the mandrel, and as a spacer means for adjusting the length of portion 26 whereby to regulate the axial inward movement of the mandrel relative to the sleeve, as will be subsequently described. The body of expander 22 is provided with a plurality of narrow, angularly spaced, longitudinally extending key slots 20.

whereby these members may be relatively slidable longitudinally but will :be locked against relative rotation. This arrangement, as best seen in Figs. 6 and 8, provides longitudinally spaced rotary drive connections between the adjacent upper and lower portions of the mandrel and the sleeve.

The portion of sleeve 30 intermediate the sets 'of lugs 3| and 55 and opposite expander 22 is provided with an inwardly and downwardly tapered portion 33 generally concentric with the exterior surface of expander 22. Tapered portion 33 of the sleeve is provided with a plurality of narrow elongated openings or windows 34, equal in number to, and registering with, key slots 2D. The lower end of sleeve 35 has an enlarged bore 5S, and is threadedly connected to a tubular base member 51, having in its upper portion a cylindrical chamber 58 forming a coaxial extension of enlarged bore B, and adapted to receive cylindrical portion 26 carrying washers 28 and nipple 29. Chamber 58 has a bottom forming an internal abutment or shoulder 58a engageable with the lower end of nipple 23 to limit inward movement of mandrel Il in sleeve 3D. Chamber 58 communicates with a passage 59 which opens through the lower end of base member 51. exterior of the lower end portion of base member 51 is downwardly and inwardly tapered to form a generally conical nose 51a.

Disposed in each of the openings or windows 34, is a pipe roller assembly, designated generally by the numeral 35. Each roller assembly includes an elongated roller support bracket di] disposed in a window 34 and having an inner face 4l disposed in abutting sliding engagement with the tapered exterior surface of expander 2.2. Inner face 4l has thereon a longitudinally extending inwardly projecting key 44 (Figs. 3 and '1) which extends intothe adjacent key slot 28 for longitudinal sliding movement therein. The

outer face of each bracket 4G is shaped to relower ends of keys 44 of brackets 40 to prevent the mandrel from being drawn upwardly out of sleeve 3U.

Leaf springs 5B are secured .by screws 5l to the exterior of sleeve 30 above and below the ends of each window 34 and have free ends extendingV in front of the upper and lower ends of bracket Vlill to resilient-ly retain the roller assembly in place within the window while permitting limited radial outward movement of the roller assembly.

Base member 51 may have mounted in the exterior surface thereof, preferably in recesses 51 provided in nose 51a, a plurality of angularly spaced, frusto-conical guide rollers 50 provided with upper and lower spindles E2 and El, respectively, lower spindle Bi being journalled in the bottom wall of 'a recess 61 and upper spindle 62 being journalled in a Aclip E3 mounted on 'the exterior of the base member adjacent the upper end of recess 61. These guide rollers serve to guide and center the tool as it'enters the de- The l the end of portion '26.

4 formed portion of the pipe or casing in the well.

When assembled as seen in Fig. 1, cylindrical portion 28 of the mandrel carrying the washers 28 and lock nipple 29 will extend sl-idably into enlarged bore 5B and chamber' 58 which thus provide a lateral thrust bearing for the lower end of the mandrel. Drive lugs IE and 25 will be engaged, respectively, with lugs 3l and 55, and roller assemblies 35 will be slidably engaged with expander 22.

Fig. 3 shows the particular mounting of the bracket d!) in sleeve 3! wherein the transverse pins 65 are mounted in elongated recesses 56 so that the bracket may have some radial sliding movement with respect to the sleeve but wherein the pins 65 hold the bracket against displacement when the tool is in operation.

The above-described device operates in the following manner: When the device is run into pipe 2, mandrel H will be held in the elevated position relative to sleeve 35, as illustrated in Fig. 1, so that the roller assemblies will be in the radially retracted positions as also illustrated in Fig. 1.

When nose 51a strikes indented portion 3 of the pipe as the tool is lowered therein, further downward movement of the tool will be temporarily arrested. A suiiieient portion of the weight of the operating pipe string will then be imposed on mandrel Il to ybreak a shear pin or other conventional releasable mem-ber (not shown) which is employed to initially hold the mandrel in the relatively elevated position and the weight thus applied to the mandrel'will force the mandrel downwardly relative to the sleeve, which will, of course, be held stationary by the engagement of base member 51 with indented portion 3. Expander 22 will thereby be forced downwardly between the roller assemblies 35 and will urge rollers 35 radially outwardly into rolling contact lwith the wall of casing 2. Thereafter, rotation of the operating pipe will ybe transmitted from mandrel I l through the engaged sets of drive lugs 16, 31 and 25, 55 to sleeve 35 to rotate the rollers 36 against the pipe wall and as the tool is advanced under the weight of the operating pipe, the rollers will be caused to expand indented portion 3 to the desired diameter, which will usually be the normal diameter of pipe 2.

It will be obvious that the extent to which rollers 35 will be radially expanded will be determined by the extent of downward movement of the mandrel relative to s1eeve30, which will be limited by the distance between the lower end of nipple 29 and the bottom of chamber 58, as seen 'in Fig. 4. lThis distance may be varied. .by vary- 4ing the number and length of the washers 28 and the extent to which lock nipple 29 is run upon Thus, by appropriate variation of the latter the extent of radial projection of rollers 35 may be controlled to match the diameter to which the indented portion of the pipe or casing is to be expanded.

When rolling of the pipe is completed, the tool may be withdrawn from the pipe by pulling upwardly on operating pipe string I3 which will pull the mandrel upwardly relative to the sleeve, the weight of the latter and frictional drag of rthe rollers on the wall of pipe 2 tending to hold the sleeve in the relatively downward position.

vExpander 22 will then move 'upwardly from besion of an expansible casing roller where the ex pansion is accomplished by relative longitudinal sliding movement between an expanding mandrel and a roller `supporting housing.

What is claimed is:

1. A pipe expander for expanding collapsed areas of a pipe inside a well bore, comprising, a mandrel insertible in a well pipe and having a downwardly tapered expander portion intermediate its ends, a tubular sleeve surrounding said mandrel, a plurality of angularly spaced openings in the wall of the sleeve opposite said expander portion, pipe roller assemblies movably mounted in said openings and having longitudinal sliding engagement with said expander portion, whereby said roller assemblies are radially projectible from said opening-s by downward movement of the mandrel relative to the sleeve, longitudinally slidably engaged rotational drive connections between said mandrel and said sleeve above and below said expander portion, and means for connecting said mandrel to an operating member extending to the top of the well.

2. A pipe expander according to claim 1 wherein each of said roller assemblies comprises a roller support bracket, and a longitudinally disposed frusto-conical pipe roller having its ends journalled in said bracket.

3. A pipe expander for expanding collapsed areas of a pipe inside a well bore, comprising, a mandrel insertible in a well pipe and having a downwardly tapered expander portion intermediate its ends, a tubular sleeve surrounding said mandrel, a plurality of angularly spaced elongated openings in the wall of said sleeve opposite said expander portion, a pipe roller assembly disposed for radial movement in each of said openings and having longitudinal sliding engagement with said expander portion, whereby said roller assemblies are radially projectible from said openings by downward movement of the mandrel relative to the sleeve, adjustable means arranged between the lower end of said mandrel and said sleeve to adjustably limit the extent of downward movement of the mandrel relative to the sleeve, longitudinally slidably engaged rotational drive connections between said mandrel and said sleeve above and below said expander portion, and means for connecting said mandrel to an operating member extending to the top of the well.

4. A pipe expander according to claim 3, wherein said expander portion is provided with a plurality of elongated key slots registering with said openings, and wherein said pipe roller assembly includes an elongated support bracket having a key member projecting into said key slot, and a longitudinally disposed frusto-conical pipe roller having its ends journalled in said bracket.

5. A pipe expander according to claim 3 wherein said adjustable means comprises a threaded extension on the lower end of said mandrel, spacer members threadedly mounted on said extension to vary the length thereof, and abutment means in said sleeve abuttably engageable with the lower end of said extension member.

6. A pipe expander for expanding collapsed areas of a pipe inside a well bore, comprising, a mandrel insertible in a well pipe and having a downwardly tapered expander portion intermediate its ends, a tubular sleeve surrounding said mandrel, a plurality of angularly spaced openings in the wall of Isaid sleeve opposite said expander portions, roller assemblies movably mounted in said openings and having longitudinal sliding engagement with said exp-ander portion, whereby said roller assemblies are radially projectible from the sleeve by downward movement of the mandrel relative to the sleeve, internal abutment means in the lower portion of said sleeve engageable with the lower end of the mandrel to limit the extent of downward cmovement of the mandrel in the sleeve, longitudinally slidably engaged rotational drive connections between said mandrel and said sleeve above and below said expander portion, and means for connecting said mandrel to an operating member.

7. A pipe expander according to claim 6, wherein the lower end of said sleeve terminates in a downwardly and inwardly tapered portion having a plurality of angularly spaced guide rollers mounted on the exterior thereof.

PAUL B. CLARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 212,964 McGraw Mar. 4, 1879 743,146 Carty Nov. 3, 1903 816,451 Forwood Mar. 27, 1906 1,279,130 Leonard Sept. 17, 1918 1,312,333 Lebow Aug. 5, 1919 1,880,218 Simmons Oct. 4, 1932 2,237,538 Zublin Apr. 8, 1941 2,546,756 Knowlton Mar. 27, 1951 

